JPH051713Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a temperature compensation mechanism for an air suspension used in a vehicle or the like.

(Prior art) Air suspension structures that also have a gas cushioning function include those that form a gas chamber in the upper part of the cylinder, and those that form a gas chamber in the upper part of the outside of the cylinder via a rolling diaphragm. be.

On the other hand, the characteristics of not only air suspensions but also general hydraulic shock absorbers change due to temperature changes. As a function to compensate for this change, a temperature compensation mechanism is known in which the opening area of an orifice for generating damping force is variable.

(Problem to be solved by the invention) When the conventional temperature compensation mechanism described above is applied to a conventional air suspension, it is possible to adjust the damping force generated in response to temperature changes, but the spring characteristics due to the gas cannot be adjusted. It cannot be adjusted in response to temperature changes.

(Means for Solving the Problem) In order to solve the above problem, the present invention provides an independent oil chamber whose volume changes according to temperature changes, and moves the free piston up and down by the change in the volume of this independent oil chamber. Furthermore, the volume of the compensating oil chamber connected to the gas chamber or the oil chamber is changed by the vertical movement of the free piston.

(Function) The spring characteristics of the gas are adjusted by directly changing the volume of the gas chamber or indirectly by changing the volume of the compensation oil chamber.

(Example) An example of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a sectional view of an air suspension according to the present invention, and FIG. 2 is an enlarged sectional view of a main part of an air suspension according to another embodiment.

A seat pipe 2 is installed at the bottom of the outer tube 1 of the air suspension, and an inner tube 3 is slidably inserted from above between the outer tube 1 and the seat pipe 2, and a seat pipe 2 is installed at the bottom of the outer tube 1 of the air suspension. The case 4 is fixed and the inside of the inner tube is used as an oil chamber S1 in which hydraulic oil is sealed.

Further, a valve 5 that slides into contact with the outer peripheral surface of the seat pipe 2 is fitted on the inner peripheral surface of the lower end of the inner tube 3, and an orifice 6 that communicates between the inside and outside is formed above the valve 5. A piston portion 7 is formed at the upper end portion to be in sliding contact with the inner circumferential surface of the inner tube 3, and orifices 8 and 9 are formed below the piston portion 7 to communicate between the inside and the outside.

Further, a cylinder 10 is installed inside the outer tube 1 with a gap between the outer tube 1 and the inner tube 3, and this cylinder 1
An orifice 16 (see FIG. 2) is formed in the upper part of the tube 0 to communicate the gap between the inside and outside, that is, the gap between the outer circumferential surface of the inner tube 3 and the gap between the inner circumferential surface of the outer tube 1. Furthermore, a seat pipe 2 is attached to the cap 17 forming the bottom of the outer tube 1.
Install the hollow center bolt 18 facing inward,
These caps 17 and center bolts 18 have orifices 19 that communicate the lower part of the gap between the cylinder 10 and the outer tube 1 into the seat pipe 2.
An air guide is provided at the upper end of the center bolt to prevent air from returning from the orifice 9 of the seat pipe.

The case 4 is partitioned at the middle by a partition wall 20, and the shaft of the free piston 21 is slidably inserted into the hole formed in the partition wall 20. A large-diameter piston part 22 that slides on the surface is provided, the upper part of this large-diameter piston part 22 is a large-diameter gas chamber S2, and a free piston 21 is provided between the large-diameter piston part 22 and the partition wall 20.
The lower end of the free piston 21 is provided with an inner tube 3 at the lower end of the free piston 21.
A small-diameter piston portion 23 that slides on the inner circumferential surface is provided, a small-diameter gas chamber S4 is formed below the small-diameter piston portion 23, and a hole 21a is formed in the shaft portion of the free piston 21 to form a small-diameter gas chamber S4 and a large-diameter gas chamber S2. The partition wall 20 and the small diameter piston portion 23 communicate with each other.
There is a sealed independent oil chamber S5 between the two. Note that gas is sealed into the large-diameter gas chamber S2 and the high-pressure gas chamber S3 via air valves 25 and 26.

In the above, when the temperature rises, the oil in the independent oil chamber S5 expands and its volume increases,
Push down the free piston 21. Then, the volume of the small-diameter gas chamber S4 decreases, but the volume of the large-diameter gas chamber S2 increases, and the volume of the gas chamber as a whole increases. As a result, even if the temperature rises, the pressure within the gas chamber remains approximately constant, resulting in stable air spring characteristics.

Moreover, when the temperature falls, the volume of the entire gas chamber decreases, contrary to the above, and stable air spring characteristics are obtained.

FIG. 2 is an enlarged view of main parts showing another embodiment, and the same parts as in the previous embodiment are given the same numbers.

That is, in this other embodiment, a case 4 is integrally formed on the outside of the outer tube 1, and a free piston 21 that slides along the outer circumferential surface of the outer tube 1 is provided inside the case 4. A compensating oil chamber S6 is provided above the large diameter piston portion 22 of the piston 21 and is connected to the oil chamber S1 in the suspension via an oil hole 27.
A high-pressure gas chamber S3 is formed between the partition wall 20 and the partition wall 20, an independent oil chamber S5 is formed between the partition wall 20 and the small diameter piston section 23, and the lower part of the small diameter piston section 23 is open to the atmosphere.

In this alternative embodiment, when the temperature rises, the oil in the independent oil chamber S5 expands, the free piston 21 descends, and the volume of the compensation oil chamber S6 increases. When the volume of the compensation oil chamber S6 increases, the hydraulic oil in the oil chamber S1 in the suspension flows into the compensation oil chamber S6, and the oil level in the oil chamber S1 decreases by that amount, resulting in the increase in the gas chamber. Even if the volume expands and the temperature rises, the pressure inside the gas chamber remains approximately constant, providing stable air spring characteristics.

Furthermore, even when the temperature drops, stable air spring characteristics can be obtained in the same way.

(Effect of the invention) As explained above, according to the invention, the free piston is moved up and down in response to temperature changes, and the volume of the gas chamber is changed by the up and down movement of the free piston, so a simple mechanism is used. Stable air spring characteristics can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an air suspension according to the present invention, and FIG. 2 is an enlarged view of main parts of another embodiment. In addition, in the drawing, 1 is an outer tube, 3 is an inner tube, 4 is a case, 21 is a free piston, 22 is a large diameter piston part, 23 is a small diameter piston part, S1 is an oil chamber, S2 is a large diameter gas chamber, and S3 is a high pressure gas chamber, S4 is a small diameter gas chamber, S5 is an independent oil chamber, and S6 is a compensation oil chamber.

Claims (1)

[Claims for Utility Model Registration] (1) In an air suspension in which gas is filled together with hydraulic oil, the gas chamber is divided into a large-diameter gas chamber and a small-diameter gas chamber by a free piston, and these large-diameter gas chambers are divided into a large-diameter gas chamber and a small-diameter gas chamber. The small-diameter gas chamber and the small-diameter gas chamber communicate with each other through a through hole formed in the shaft portion of the free piston, and the free piston moves up and down due to volume changes in response to temperature changes in the independent oil chamber, and connects the large-diameter gas chamber and the small-diameter gas chamber. A temperature compensation mechanism for an air suspension characterized by changing the volume of a gas chamber. (2) In an air suspension in which gas is sealed together with hydraulic oil, a compensating oil chamber is provided outside the outer tube of the suspension and is defined by a free piston and communicates with the oil chamber within the suspension; The temperature compensation mechanism for an air suspension is further characterized in that the free piston moves up and down as a result of a volume change corresponding to a temperature change in the independent oil chamber, thereby changing the volume of the compensation oil chamber.